Tamoxifen can be a preventive measure against breast cancer for certain women.
This is according to research published in Cancer, a peer-reviewed journal of the American Cancer Society.
The results of the research showed that the benefits of the drug in preventing cancer can sufficiently compensate for its side effects in post-menopausal women aged under 55 who have an increased risk of developing breast cancer.
These beneficial effects even last for years after the tamoxifen treatment ends.
Unfortunately, there is some difficulty in identifying which women stand to gain from the treatment.
This is due to the problematic side effects of the drug, which include pulmonary embolism, endometrial cancer, deep vein thrombosis and cataracts.
Dr Peter Alperin, who researched the drug with his colleagues at Archimedes Inc., used a mathematical model to conduct a virtual clinical trial with the aim of identifying the group with most to gain.
He noted that post-menopausal women aged 55 years and younger with a five-year risk of developing breast cancer of 1.66 per cent or greater stand to benefit most from using tamoxifen to prevent breast cancer because in this group it can "save lives and has a low frequency of side effects".